Dental instrument holder



April 8, 1952 c. G. KING 2,592,292

DENTAL INSTRUMENT HOLDER Filed June 30, 1949 INVENTOR. Clifford 6. King ATTORNEY Patented Apr. 8, 1952 UNH'E'ED STATES PATENT OFFICE DENTAL INSTRUMENT HOLDER Ciifiord G. King, Providence, R. 1.

Application June 30, 1949, Serial No. 102,365

7 Claims.

My invention relates to improvements in dental instrument holders, particularly those of the type adapted to hold drills, burrs and other dental instruments, comprising a casing having a rotating dental instrument projecting therefrom and usually driven by a drive shaft at right angles thereto in the holder, adapted to be manipulated by the dentist to press the rotating instrument against the users teeth. No matter how careful a dentist was, it always seemed to the patient that the drill was being pressed too hard.

A main object of my invention is to provide a construction of this description, in which the rotating instrument may be pressed against the teeth with extremely light pressure, and in which the pressure will always be cushioned in a marked degree. The very light pressure obtainable by my invention reduces impact, trauma, static electric shock, heat, noise, and discomfort to the patient bein operated upon.

As it is apparent that the instrument is applied with less pressure and often with less pain to the patient, it is apparent that the speed of rotation of the instrument may be greatly increased, so as to increase the efficiency of the devices of this description in their actual teeth contacting operations.

My invention is particularly efficient when used in high speed drills or burrs of a type which have recently come on the market, which require high revolutions per minute and which operate more efficiently with light pressure, thereby making available this new type of instrument for dental use.

Further features of my invention relate to the specific structure of the various parts of my inproved dental instrument holder.

A further object of my invention, therefore, is to make a major change in the mode of operation of a dental instrument holder by a correspondingly small change in the structure of the holder itself by introducing a minimum of new elements and making the present elements in such holders perform double functions, namely, their old function, and a new function inherent in the operation of my invention.

These and such other objects of my invention as may hereinafter appear will be best understood from a description of the accompanying drawings which illustrate an embodiment thereof.

In the drawings,

Fig.- 1 is a perspective view of an embodiment of dental instrument holder constructed in accordance with my invention employing a burr as the instrument.

Fig. 2 is a vertical sectional view of the holder shown in Fig. l in non-operating position.

Fig. 3 is a vertical section of the same holder shown in Fig. 2 showing the parts in cushioning operating position with the application of downward pressure to the burr.

Fig. 4 is a transverse section taken along the line 44 of Fig. 2.

Fig. 5 is a cross section taken along the line 55 of Fig. 2.

Fig. 6 is a perspective view of the flat cushioning spring and retaining member I preferably employ.

Fig. '7 is a perspective view of the drive sleeve member I preferably employ.

In the drawings, wherein like characters of reference generally indicate like parts throughout, I!) indicates a dental instrument holder constructed in accordance with my invention. My dental tool holder I0 is provided with a cylindrical extension l2 from the inner wall 14 of said holder I!) for containing the drive shaft Hi thereof, which is contained in the flexible casing 18 connecting said extension l2 to a source of power for rotating the drive shaft l6. Said extension I2 is provided with the reduced end portion 20 having a portion 22 of larger diameter beyond it. providing a marked shoulder 24 at the point of enlargement of said extension between said reduced portion 20 and enlarged portion 22. The holder H) is made of generally oblong formation and has the opening 26 for receivin the drive shaft 15 at the inner end thereof and a dental tool receiving hole 28 extending vertically from top to bottom at the outer end thereof normal to the end of said drive shaft 16, specifically providing the lower opening 30 in the holder casing bottom wall aligned with an upper opening 32 in the casing top wall. Said lower Opening 30 has a threaded bore 34 of relatively large size at its lower end and a bevel gear 35 above it. Said hole 28 is adapted to contain the usual drive sleeve 38, to which the driven bevel gear 36 is attached or made integral with. The casing body I0 is also provided with a screw hole 62 in the upper end thereof aligned with said upper opening 32. The drive shaft l6 extends through the drive shaft opening 26 and has the usual driving bevel gear 44 mounted on the end thereof in mesh with the bevel gear 36 mounted on the drive sleeve 38. The sleeve 38 is provided with a flat portion-46 projecting radially inwardly from the upper end thereof. A nut 48 is provided having a threaded periphery adapted to be threaded within the enlarged lower threaded portion '34 of said hole 28 for supporting said sleeve 38 and integral driven gear 36 thereon.

Each instrument 58 is provided with the reduced neck portion 52 adjacent the upper end thereof and a cap portion 54 above it with the upper portion of said instrument and. said cap portion having a peripheral flat portion 56 adapted to abut the flat portion 46 in the upper end of the sleeve, so that said instrument may be rotated on rotation of said sleeve. Suitable means are provided to detachably latch the upper end of the instrument 58 to the casing for rotary movement thereof. While various means may be provided for this purpose, I prefer to mount a screw 68 within the screw hole 42 in the upper wall of the casing I8 and. pivotally mount thereon a flat member 62 having a hook or other means at the outer end thereof, adapted to engage the restricted neck 52 of the instrument to permit rotary movement thereof but to retain it in attached position within the sleeve 38 with the flat portions 46 and 56 abutting to provide rotary movement of the instrument 58 with the rotating sleeve 38. For this purpose the flat locked member is pivoted on the screw 68 so that its hooked front end will pivot to engage within the neck 52 of said instrument. To receive the hooked portion of said member, a lateral slot is provided in the casing so that the cap 54 of the instrument 50 will abut the portion of the casing above the slot to positively prevent any axial movement of the instrument 58 and the sleeve 38.

To carry out the principles of my invention, namely to provide limited axial movement of the instrument 58, I have provided a portion 68 of smaller bore than the hole 38 immediately above the threaded portion 34 of the lower end thereof for receiving the annular flange 18 of the bevel gear 36 underneath the shoulder 12 provided by said enlarged bore 68 to positively secure said driven gear 36 against axial movement, and keep the teeth thereof continuously in mesh with the teeth on the drive gear 44 on the end of the drive shaft I6. I have maintained the hole 28 in said casing of suflicient size to permit axial movement of the sleeve 38 upwards through the upper end 32 of said hole 28. To provide means to rotate the sleeve 38 on rotation of said gear 36, I provide an axial spline I4 projecting inwardly from said gear 36, and I provide the axial slot 16 extending upwardly from the bottom of said sleeve 38 for receivin the gear key or spline 14 for rotary movement of said sleeve 38 by said gear 36 yet permitting the axial movement of said sleeve 38 relative to said gear 36 with said slot 16 sliding upwardly relative to said key or spline I4, yet maintaining it within for rotary movement thereof. I also preferably provide the annular flange I8 projecting outwardly from the upper end of said sleeve 38. If desired, I may provide a suitable washer 88 surrounding the edge of the flange I8.

' I provide the means to cushion axial movement of sleeve 38 and/or instrument 58 by providing a slideable member 62 which is slideable longitudinally of said casing or axially of said drive shaft I6, and to keep said slideable member 62 in longitudinal alignment with the single screw 68 I provide the supplemental screw 82 in alignment therewith and for another purpose to be described. As means to limit the upper axial movement of the sleeve 38 and shaft 58 I provide the cap member 84 for the upper end of the casing having cooperating screw holes 86 and 88 therein aligned respectively with the screw holes 98 and 42 for the respective screws 82 and 68, it being obvious that the screws 68 and 82 secure the cap member 84 to the casing.

I preferably construct the retaining member 62 out of resilient flat stock and provide it with the rolled-over handle 88 adapted to engage the shoulder 24 when the slideable retaining member 62 is slid forward to retaining position, said member thus being retained in locked position with its handle 88 abutting said shoulder 24. The cap 84 is provided with the slot 92 in the lower portion of the inner wall thereof to receive said slideable member therethrough. Said slideable member 62 has an elongated slot 94 adjacent the outer end thereof for receiving the screws 68 and 82 therein for longitudinal movement thereof relative thereto substantially longer than the distance between the screws. Said slideable and cushioning retaining member 62 has the outer end thereof bent upwardly as at 86 and then inwardly as at 98 to form a hood, the tip I88 thereof overlying the outer end of said fiat retaining member. The slot 94 limits the longitudinal movement of the slideable member 62. Said member 62 is also provided with a circular hole I82 immediately below the overlying tip I88 and having the axial channel I84 projecting inwardly therefrom terminating in the circular end portion I86 of smaller diameter than said hole. It is apparent that the retaining member 62, as it is resilient, will function to cushion the axial movement of the operating sleeve 38 and instrument 58 during the operation of said instrument. If desired, however, sensitive spring means I88 may be provided for this purpose specifically to abut the upper surface of said retaining member 62 near the inner end thereof within the casing and urge it downwardly after its outer end has become attached to the upper end of the instrument 58. For this purpose I provide the elliptical coil spring I88 having its lower end abutting the upper surface of the retaining member 62 and its upper end abutting the cap top wall I I8. It may, if desired, as shown in Fig. 4, have its ends II2 bent and looked around the screw such as the screw 68 to prevent sliding movement thereof.

Itis apparent that with this construction if it be desired to insert an instrument 58 within the hole 28, the shank .Il4 thereof is inserted upwardly in the hole 28, leaving the working part I I 6 such as the burr shown projecting downwardly therefrom, and for this purpose the handle 98 of the slideable member 62 is pulled upwardly from the shoulder 24 and then pulled longitudinally inwardly to bring the circular hole I82 in the end thereof and overlying tip I88 immediate over the center of the sleeve 38, so that as said instrument 58 is inserted upwardly it is first inserted so that its flat portion 56 is brought opposite the fiat portion 46 on the sleeve 38, and the cap 54 thereof is inserted upwardly through said circular hole I82. The handle 98 may then be manipulated so as to push the slideable member 62 outwardly, causing the neck 152 of the burr to lie within the axial channel I84 thereof with the adjacent portions of said member fitting within the neck 52. This effectively retains the instrument 58 to the sleeve 38 and to the end of the resilient slideable member 62, so that they may pivot upwardly from the slot 92 therefor in the outer wall of the cap member 84 as a fulcrum to the position shown in Fig. 3. It is apparent that the overlying wall of the tip Hill of said slideable member abuts the cap 54 of said instrument to provide an end bearing therefor, and to fasten said resilient spring member 62 to said sleeve 38 and instrument 50 to cushion any axial movement thereof, and that said coil spring 18 also may abut said spring member 62 to increase the cushioning effect thereof. It is thus apparent that when applied against a tooth, as shown in Fig. 3, that is, during the operation of the burr, drill or other dental instruments, the sleeve 36 and attached instrument will slide axially upwardly due to the resiliency of the retaining member 62 and that the spring I08 will provide a yielding cushioning movement until the upper end of the tip Hill of said slideable member 62 abuts the upper wall of cap 84 to limit the axial movement thereof. To remove the instrument it is necessary merely to pull the retaining member 62 outwardly, when the cap of the instrument will drop downwardly through the circular hole I82.

It is apparent that I have provided a novel type of dental instrument holder with the advantages described above.

It is understood that my invention is not limited to the specific embodiment shown and that various deviations therefrom may be made without departing from the spirit and scope of the appended claims.

What I claim is:

1. A dental instrument holder comprising a casing having an instrument receiving hole extending upwardly therethrough, a driven bevel gear mounted for rotation and against axial movement within the hole, a drive shaft extending inwardly within said casing having a drive bevel gear on the end thereof in mesh with said driven bevel gear, an axially movable tool containing drive sleeve mounted for rotation within said driven bevel gear having an inner periphery shaped to hold and drive an inserted dental instrument having a contracted neck portion adjacent its upper end, a cap for the upper end of said casing, a fiat retaining and cushioning spring member longitudinally slideable over said casing having a sliding handle at the inner end thereof and a tip within said cap portion, bent backwards on itself to abut the top of an instrument inserted within said sleeve having an instrument top receiving opening and an instrument neck receiving extension connected thereto below the overlying tip of said slideable member whereby the upper end of a dental instrument inserted within said drive sleeve may be passed through said instrument top receiving hole in said slideable member to abut said handle member tip to align the instrument neck with an axial channel, connected with said hole and said channel may be locked around said neck on outward sliding movement of said retaining member whereby said instrument is mounted on said sleeve in said casing for rotary movement and for cushioned axial movement thereof, and said axial movement of said instrument is limited by said retaining member tip abutting the top cap wall, and elliptical coil spring means mounted to have its upper end abut the cap to wall and its lower end abut the resilient retaining member to cushion the axial movement of said instrument.

2. A dental instrument holder comprising a casing having an instrument receiving hole extending upwardly therethrough, a driven bevel gear mounted for rotation and against axial movement within the hole, a drive shaft extending inwardly within said casing having a drive bevel gear on the end thereof in mesh with said driven bevel gear, an axially movable tool containing drive sleeve mounted for rotation within said driven bevel gear having an inner periphery shaped to hold and drive an inserted dental in strument having a contracted neck portion adlacent its upper end, a cap for the upper end of said casing, a flat retaining and cushioning spring member longitudinally slideable over said casing having a sliding handle at the inner end thereof and a tip within said cap portion, bent backwards on itself to abut the top of an instrument inserted within said sleeve having an instrument top receiving opening and an instrument neck receiving extension connected thereto below the overlying tip of said slideable member whereby the upper end of a dental instrument inserted within said drive sleeve may be passed through said instrument top receiving hole in said slideable member to abut an axial handle member tip to align the instrument neck with said channel connected with said hole, and said channel may be looked around said neck on outward sliding movement of said retracting member whereby said instrument is mounted on said sleeve in said casing for rotary movement and for cushioned axial movement thereof, and said axial movement of said instrument is limited by said retaining member tip abutting the top cap wall and spring means mounted to have its upper end abut the cap top wall and its lower end abut the resilient retaining member to cushion the axial movement of said instrument.

3. A dental instrument holder comprising a casing having an instrument receiving hole extending upwardly therethrough, a driven bevel gear mounted for rotation and against axial movement within the hole, a drive shaft extending inwardly within said casing having a drive bevel gear on the end thereof in mesh with said driven bevel gear, an axially movable tool containing drive sleeve mounted for rotation within said driven bevel gear having an inner periphery shaped to hold and drive an inserted dental instrument having a contracted neck portion adjacent its upper end, a cap for the upper end of said casing, a flat retaining and cushioning spring member longitudinally slideable over said casing having a sliding handle at the inner end thereof and a tip within said cap portion, bent backwards on itself to abut the top of an instrument inserted within said sleeve having an instrument top receiving opening and an instrument neck receiving extension connected thereto below the overlying tip of said slideable member whereby the upper end of a dental instrument inserted within said drive sleeve may be passed through said instrument top receiving hole in said slideable member to abut an axial handle member tip to align the instrument neck with said channel connected with said hole, and

' said channel may be locked around said neck on inner end thereof and containing the drive shaft having a reduced portion adjacent the outer end thereof, forming a shoulder, and the handle for said slideable member, when moved outwardly to a position latching the neck of the instrument thereto, may be moved to a locked position abutting said shoulder.

5. A dental instrument holder comprising a casing having an instrument receiving hole extending upwardly therethrough, a driven bevel gear mounted for rotation and against axial movement within the hole, a drive shaft extending inwardly within said casing having a drive bevel gear on the end thereof in mesh with said driven bevel gear, an instrument-containing drive sleeve mounted for rotation within said driven bevel gear, said drive sleeve having an inner periphery shaped to hold and drive an inserted dental instrument and being axially movable during the operation of said instrument, means to detachably secure said inserted instrument to said drive sleeve against relative axial movement, and resilient means urging the upper end of said sleeve to a lowered position against up,- ward axial movement resulting from the pressure of said instrument against the member operated upon, thereby providing a cushioned axial movement of said instrument during the operation of the latter said resilient means comprising a 1ongitudinally slideable cushioning retaining member and means thereon for detachable securement to the upper end of the instrument, said resilient cushioning means abutting the upper surface of said slideable retaining member.

6. A dental instrument according to claim 1, wherein two aligned screws extend downwardly through the top cap wall through the retaining member and into the casing to keep; the slideable retaining member axially aligned with the drive shaft, and for looping said elliptical spring around them and locking the ends thereof thereto.

'7. In a dental machine instrument holder hav- REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 493,846 Weber et a1 Jan. 21, 1893 1,142,443 Krebs June 8, 1915 1,292,632 Nemmers Jan. 28, 1919 2,231,969 Tifit Feb. 18, 1941 FOREIGN PATENTS Number Country Date 660,976 Germany June 7, 1938 

